Today's battery management units (BMU's) and power management units (PMIC's) for devices powered by rechargeable batteries typically use coulomb counting to track the state of charge (SOC) of the battery. Error concealment is a possibility for improving SOC tracking because the coulomb counting not only accumulates the battery current Ibat(t) over time but also the error ε(t) of the measurement. So, after a longer run time, the tracking error can grow significantly and thus impact the accuracy of the SOC result. As a remedy, error concealment may be used: after a certain period, the SOC derived from coulomb counting is re-calibrated to cancel the accumulated error.
Disadvantageously, known methods require the device, respectively, the battery to be put into a specific state, but the specific condition may not be met during normal use of a portable battery powered device. In other words, known methods are not suitable to perform error concealment in a real-time environment, i.e. during normal operation of the battery powered device.